1. Field of the Invention
The present invention relates in general to an optical communication of information and more particularly to a system and a method for optically communicating information between a display and a camera that is observing the display.
2. Related Art
Optical communication between an image source (such as a display) and an image detector (such as a camera) is desirable and has several applications. By way of example, if a computer network contains several devices and sensors within a large physical space, the addition of a new device (such as a display or a camera) could be greatly simplified if the display and the camera were in optical communication. The display and camera would simply establish an optical communication link and transmit information (such as a network address). In this manner a new device could be connected to the computer network automatically and without human intervention.
Unfortunately, there are few techniques currently available that permit optical communication between a display and a camera. There are some techniques, however, that allow optical communication between other types of devices. For example, one technique facilitates data transmission between a display and a watch having a photosensor. This technique permits data to be downloaded from the computer (via the display) to the watch memory. One disadvantage, however, of this technique is that a large degree of human intervention is required to facilitate the download. In particular, the user must hold the watch up to the display for the duration of the download, which can be tiring for the user and lead to inaccurate and incomplete data transmission. In addition, this technique and others have the disadvantage of not being able to automatically determine the spatial location (or pose) of the display relative to the camera observing the display. Knowledge of the display pose is important because when the pose is known the system is able to include the display and camera in any physically-based user interface. For example, if the system wants to send a user a visual message, it is necessary to select a display that the user can actually see. If the cameras (or appropriate hardware) are used to track the location of the user, then the physical relationship between user and camera can be determined. By repeating this process for all displays, it is possible to select the display that is in the most advantageous location for interacting with the user.
Accordingly, there exists a need for a system and method for optically communicating information between a display and a camera that is automatic and does not require any human intervention. This system and method would allow a variety of information to be transmitted between the display and camera to facilitate, for example, automatic connection of a new device to a computer network. In addition, this system and method for optically communicating information would enable a pose of the display to be determined relative to the camera. Whatever the merits of the above-mentioned systems and methods, they do not achieve the benefits of the present invention.